Peel, pit and chop the mangoes.,In a food processor, puree the mango, stopping once or twice to scraps down the sides of the work bowl.,______,In a pitcher, combine the mango puree, water, lemon juice and sugar; stir well to dissolve.,cover and refrigerate until very cold, at least 5 hours and preferably overnight.,Taste and add additional sugar if desired.,Pour the lemonade over ice in tall glasses.,Garnish with mint if desired and serve immediately.